Orthodontic treatment often requires the banding of teeth. In order to effect such banding, there must be sufficient space between adjacent teeth to permit the insertion and placement of the orthodontic bands. If adjacent teeth are too close together, it is necessary to create a space between them through the introduction of a mechanical force.
In the past, numerous devices have been utilized to create the necessary space between adjacent teeth, including elastomeric modules, twisted brass wire and metal spring devices (such as the stainless steel TP spring marketed by TP Orthodontics, Inc. of LaPorte, Ind. and the nickel titanium alloy NEET Spring marketed by PDS Products of Santa Ana, Calif.).
Each of these previously used devices has proved effective for generating the required space between adjacent teeth, but each has certain disadvantages.
Elastomeric modules work well in situations where the teeth are slightly mobile, as is often true of children. However, situations involving tight contacts may lead to the distortion or breakage of the elastomeric modules.
Twisted brass wire is effective in situations where the contact between adjacent teeth is too tight to permit the use of elastomeric modules. The use of twisted brass wire may, however, give rise to severe patient discomfort due to the application of substantial nonresilient forces. Further, the ends of the twisted wire tend to irritate the patient's interproximal gum tissue once in place.
Both the TP spring and the NEET spring may also be used in instances where the contacts are too tight for the use of elastomeric modules. However, both springs utilize a design having sharp wire ends which can irritate the patient's interproximal gum tissue both at the time of insertion and during use. These sharp ends also present a more serious patient hazard--they enhance the possibility that the device may become lodged in the patient's throat, causing choking, if aspirated. Further, if such a device is swallowed, the sharp ends can cause intestinal damage.
In addition to the fact that the previously used orthodontic springs incorporate irritating and potentially dangerous sharp end designs, these springs are also made of round wire stock, which creates an enhanced potential for occlusal interference due to the fact that the wire has the same dimensions in all directions. In other words, if the gauge of the round spring wire is increased to enhance the spacing forces provided, then, by necessity, this will also increase the extension of the wire through the occlusal plane--thereby interfering with the patient's masticatory processes.
Thus, the need exists for a spacing device which may be used in situations involving tight contacts and which will minimize irritation to patients' interproximal gum tissue and the potential for injury arising from sharp wire ends. There is also a need for a tooth spacing device having a cross section which permits spacing forces to be optimized while minimizing occlusal interference.